Scared about Weight Loss and other symptoms!

Hi! I am new to this site, and am hoping for some reassurance and just someone to listen to my story! It is kind of long, so I apologize :)
I have had back pain since I had my son, 3 years ago. I had learned to deal with it, but in January I started to have some hip pain as well as abdominal pain, mostly when I bent over to pick something up or got out of a chair. I went to a walk in doctor at the time, and he mentioned something about Endometriosis and sent me for a full abdominal/pelvic ultrasound. The results came back clear! I then finally had a MRI on my back, which showed that I have 2 herniated lumbar discs :weep:. I was having some other symptoms at the time as well, heartburn like crazy some headaches only on one side, lump in my throat feeling. When I finally made it to my family doctor, he brushed everything off and said that it was probably Anxiety from all of the stuff that had been going on in my life at the time. He started me on 25mg of Zoloft.. and then upped the dosage to 50mg which is where I have stayed. I feel a bit better mentally than I did, but it has not taken away the symptoms that I was having. I am sure I have had almost every test there is out there and there are still some things going on that worry me! I just do not know what to do anymore, and where to go now. I worry that they are missing something, but everyone I talk to says that with all of the test that I have had they would have noticed something out of whack if it was really serious. In the first few weeks after all of the started going on, I lost my appetite. Did not feel like eating much for 2 weeks or more and lost 20lbs!!! Which of course scared me, and still does! I was diagnosed with Acid Reflux and put on pills for it, my appetite is back but I cannot gain any of the weight back! So now my big worry is that I have some type of cancer that they cannot find and that is why I am losing weight! I know I should have a bit more faith in the doctors that I have seen, but there is just something that keeps making me think they are missing something. I still have some appointments, to try and find out what is causing the weight loss and acid reflux/abdominal pain etc. and I am hoping to get some answers but I was wondering if anyone has any reassurance for me lol I will list all of the tests I have had and the results and hopefully someone can tell me if I should stop worrying so much about something scary!
August 2013- Full Physical- All Clear
October 2013- Ct Scan on brain- Clear
January 2014-Urine Test x2- Clear
January 2014- Routine Blood work at hospital- All good
January 2014- Internal Pelvic Exam- All good
January 2014- Abdominal/ Pelvic and Transvaginal Ultrasound- Only thing that was noticed was a functional Cyst
February 2014- Lumbar Spine MRI- 2 Herniated Discs L4-L5, and L5-S1
February 2014- Chest X-ray- All good
March 2014- Barium Swallow- Acid Reflux
March 2014- 2 ECG's- All good
March 2014- Blood Clot Blood Test- All good
April 2014-Gastroscopy- Saw Mild Inflammation in stomach, and was doing more tests- also he noticed my previous blood tests showed elevated ALP enzymes but after doing more blood work says it is not from Liver Disease ( Still waiting for follow up appointment with him on may 1)
April 2014- CBC and LFT- ALP enzymes are still high but he says the other blood tests are all normal
April 2014- Cardiac Stress Test- All good
April 2014- Breast Ultrasound- All good

So as you can see I have had many tests, but I am not sure if there is more I should be asking or looking for.. I think part of the reason I get so worried is that my sister in law at the age of 28 died of Cervical cancer... all because she did not go to the doctor.. so now I feel as though I need to make sure the doctors are checking everything! I really hope I am not the only one out there like this.. lol Thanks for reading :)